An imaging system detects and conveys the information that constitutes an image. An imaging system may do so by producing a signal that represents location-dependence of a characteristic (e.g., the intensity, phase, and polarization) of radiation after the radiation has interacted with a subject. For example, the radiation detected by the imaging system may be a radiation that has penetrated or reflected from the subject. The signal may be an electric signal such as an electric voltage or current. The radiation an imaging system may detect is not limited visible light, but can be electromagnetic radiation in other wavelengths (e.g., infrared, ultraviolet, X-ray, γ-ray) or non-electromagnetic radiation (e.g., α-ray and β-ray). An imaging system at least should have a radiation detector with spatial resolution. An imaging system may also have a radiation source.
One type of radiation detectors is based on interaction between the radiation and a semiconductor. For example, a radiation detector of this type may have a semiconductor layer that absorbs the radiation and generate charge carriers (e.g., electrons and holes) and circuitry for detecting the charge carriers. As used herein, the term “charge carriers,” “charges” and “carriers” are used interchangeably. A radiation detector may have multiple pixels that can independently determine the local characteristic of the incident radiation. The charge carriers generated by the radiation may be swept under an electric field into the pixels. If the charge carriers generated by a single particle (e.g., photon) of the radiation are collected by more than one pixel (“charge sharing”), the performance of the radiation detector may be negatively impacted.